This thesis presents an investigation into the transcriptional regulation of TaxolTM biosynthsis in Taxus cuspidata cell suspension cultures. The potent anticancer drug TaxolTM has been shown to be successful in the treatment of breast, lung and ovarian cancer and the acquired immunodeficiency syndrome (AIDS) related Kaposi’s sarcoma. Produced by all species of yew, TaxolTM belongs to the class of taxane diterpenoids and is of huge pharmaceutical importance. The plant material utilised in this thesis is a cell suspension culture initiated from isolated procambium cells of T. cuspidata. The latter is a meristematic tissue giving rise to the conductive tissue of plants. This un-differentiated cell suspension culture exhibits an increased and stable production of TaxolTM in response to the plant hormone elicitor methyljasmonate, limited cell aggregation and fast growth when compared to a cell suspension culture initiated from differentiated cells (somatic) of T. cuspidata. In order to assess the stem cell characteristics of the employed procambium cell suspension culture, the transcriptome of T. cuspidata was sequenced utilising Roche/ 454 and Illumina/ Solexa NlaIII tag sequencing technoloxiv gies. Statistical analysis uncovered differential expression profiles of 563 genes present within the procambium cell derived transcriptome by comparison with the somatic cell derived transcriptome. Gene ontology analysis of the latter identified that genes associated with response to stress and defence response were upregulated in the differentially expressed portion within the procambium cell suspension culture. This is consistent with the characteristics of animal stem cells which exhibit robust defence strategies to environmental stress. Furthermore PHLOEM INTERCALATED WITH XYLEM (PXY ) and TRACHEARY ELEMENT DIFFERENTIATION 2 (TED2), which are essential for ordered procambium cell division and differentiation into trachaery elements respectively in A. thaliana and Z. elegans, are up-regulated in the T. cuspidata procambium cell suspension culture. Further T. cuspidata homologues of the jasmonate signalling components JASMONATE ZINC FINGER LIKE ZIM DOMAIN 2 (JAZ2) and JAZ3 were identified among up-regulated transcripts in response to jasmonate treatment in both the procambium and the somatic cell line. Blast analysis identified 211 transcription factors within the APETELA 2 (AP2), BASIC-HELIX-LOOPHELIX (bHLH), WRKY, MYB and BASIC-LEUCIN-ZIPPER (bZIP) families. Further characterisation established 21 transcription factors which are significantly up-regulated in response to jasmonate treatment and show a higher expression level in procambium cells. These provide promising targets for further functional characterisation to elucidate their involvement within TaxolTM biosynthesis. In order to investigate transcriptional regulation of the TaxolTM structural genes, a 513 bp fragment corresponding to the TAXADIENE SYNTHASE (TASY ) promoter was cloned by genome walking. In-silico analysis of the TASY and 3’-N-DEBENZOYLTAXOL N-BENZOYLTRANSFERASE (DBTNBT) promoter resulted in the identification of methyljasmonate and pathogen-responsive elements which may significantly contribute to jasmonate mediated accumulation of TaxolTM. Analysis of a chimeric promoter construct driving the reporter gene β-GLUCURONIDASE (GUS) in N. benthamiana confirmed jasmonate-responsiveness of the TASY promoter. Finally, comparison of the expression level of genes coding for potentially rate-limiting enzymes within the TaxolTM pathway established a significantly increased expression of BACCATIN II PHENYLPROPANOYLTRANSFERASE (BAPT) in response to jasmonate treatment within the procambium cell suspension culture. Furthermore transcripts of TASY, PHENYLALANINE AMINOMUTASE (PAM) and DBTNBT show an overall higher expression and prolonged transcript accumulation in procambium compared to somatic cells. In this thesis jasmonate-signalling components, jasmonate-responsive transcription factors and differential gene expression profiles of TaxolTM structural genes were identified which, may contribute to an increased TaxolTM production in the utilised procambium cell suspension culture. Furthermore the T. cuspidata procambium cell suspension culture was found to have an increased level of stress- and defence-response reflected by differential gene expression profiles and content of phenolic compounds and TaxolTM.

Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.

Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2009.

Depuis les années 90, les études portant sur les différentes zones HNLC ont permis d'étudier les effets biologiques et biogéochimiques qu'entrainaient les enrichissements artificiels ou naturels en fer. Il est maintenant bien documenté que l'enrichissement en fer induit des blooms phytoplanctoniques et notamment des blooms de diatomées. En dehors des diatomées, très peu d'informations sont disponibles concernant les autres groupes de protistes et en particulier les protistes hétérotrophes consommateur du phytoplancton. Ce travail a été effectué dans un contexte de fertilisation naturelle en fer, dans la région des îles de Kerguélen (Océan Australe) pendant la campagne KEOPS 2 (Kerguelen Ocean and Plateau compared Study 2) lors de l'initiation du bloom phytoplanctonique et s'est focalisé en particulier sur les protistes hétérotrophes. Des approches moléculaires (tag-pyroséquençages 454) et morphologiques (microscopie) ont été utilisées afin de caractériser la structure des communautés de protistes dans la zone de référence HNLC et dans les différents blooms phytoplanctoniques. l'approche moléculaire a permis (i) de caractériser les communautés de protistes présentes (ii) de mettre en évidence des différences notables entre les structures de protistes dans la région HNLC et la région naturellement enrichie en fer, mais également entre les différents blooms. Les observations microscopiques ont révélé des tendances similaires entre les différentes régions mais aussi des liens significatifs entre les communautés microzooplanctoniques et leurs proies phytoplanctoniques. Les observations microscopiques ont également fournis des valeurs de biomasses des différents compatiments qui ont permis d'estimer le potentiel du microzooplancton en tant que consommateur du phytoplancton ou en tant que source nutritive pour le mésozooplancton. Ce travail représente la première étude caractérisant la communauté des protistes planctoniques dans son ensemble dans un contexte de fertilisation naturelle en fer. / Since the 90s, studies on different HNLC areas allowed to investigated the biological and biogeochemical effects due to artificial or natural iron-enrichment. It is now well documented that iron enrichment induced phytoplankton blooms and more specifically diatom blooms. With the exception of diatoms, very few information is available concerning other protists groups e. g. heterotrophic protists which are consumers of phytoplankton.This work was performed is a natural iron-fertilization context in the Kerguelen Island area (Southern Ocean) during the KEOPS 2 (Kerguelen Ocean and Plateau compared Study 2) cruise at the beginning of the phytoplankton bloom and focused specifically on heterotrophic protists. Molecular (tag-pyrosequencing 454) and morphological (microscopy) approaches were used to characterize the structure of protist communities in the HNLC reference area and in the phytoplankton blooms. The molecular approach allowed (i) to provide a complete picture of the protist communities (ii) to evidence significant differences in protists structures between HNLC and the naturally iron-fertilized area, but also between the different blooms. Microscopic observation revealed similar trends between regions but also significant links between microzooplanctonic communities and their phytoplankton preys. Microscopic observations also provided biomass values from different compartments allowing an estimation of the potential of microzooplankton as phytoplankton consumer or as a nutrient source for mesozooplankton. Above all, this work represents the first study characterizing the global planktonic protists community in the context of natural iron fertilization.

[by] J. Charles Ingraham and Sanborn C. Brown. / MIT-1842-36. / Bibliography: p.30-32. / Contract no. DA36-039-AMC-03200(E). U.S. AEC Contract AT(30-1)-1842.

Pyrenophora semeniperda (anamorph Drechslera campulata) is a necrotrophic fungal seed pathogen of a variety of grass genra and species, including Bromus tectorum, an exotic grass that has invaded many natural ecosystems of the U.S. Intermountain West. As a natural seed pathogen of B. tectorum, P. semeniperda has potential as a biocontrol agent due to its effectiveness at killing dormant B. tectorum seeds; however, few genetic resources exist for this fungus. Here, the genome assembly of a P. semeniperda isolate using 454 GS-FLX genomic and paired-end pyrosequencing techniques is presented. The total assembly is 32.5 Mb and contains 11,453 gene models greater than 24 amino acids. The assembly contains a variety of predicted genes that are involved in pathogenic pathways typically found in necrotrophic fungi. In addition, 454 sequence reads were used to identify single nucleotide polymorphisms between two isolates of P. semeniperda. In total, 20 SNP markers were developed for the purposes of recombination assesment of 600 individual P. semeniperda isolates representing 36 populations from throughout the U.S. Intermountain West. Although 17 of the fungal populations were fixed at all SNP loci, linkage disequilibrium was determined in the remaining 18 populations. This research demonstrates the effectiveness of the 454 GS-FLX sequencing technology, for de novo assembly and marker development of filamentous fungal genomes. Many features of the assembly match those of other Pyrenophora genomes including P. tritici-repentis and P. teres f. teres, which lend validity to our assembly. These findings present a significant resource for examining and furthering our understanding of P. semeniperda biology.

No description available.

La biohydrogénation (BH) ruminale des acides gras polyinsaturés (AGPI) est à l'origine de la production d'intermédiaires trans retrouvés dans les productions de ruminants (essentiellement le lait). Il existe deux voies de BH produisant des acides gras (AG) trans qui auraient des propriétés différentes : les isomères t11 auraient des effets bénéfiques pour la santé des consommateurs et les isomères t10 seraient responsables d'une forte diminution du taux butyreux du lait, représentant une contrainte majeure pour les éleveurs. Dans des conditions physiologiques normales, la voie t11 est fortement majoritaire, par contre avec des rations à base d'ensilage de maïs, riches en concentrés et surtout si elles comprennent des suppléments lipidiques riches en AGPI, une déviation de la voie t11 à la voie t10 peut se produire avec une augmentation significative des isomères t10 au détriment des isomères t11. L'objectif de cette thèse est d'expliquer les modalités de cette déviation, afin de mieux la maîtriser en élevage. Nos travaux permettent de conclure que les facteurs alimentaires de maîtrise de la déviation de la voie t11 vers la voie t10, sont la teneur en amidon rapidement fermentescible et la teneur en c9,c12-C18:2. Lorsque la quantité de c9,c12-C18:2 présente dans le rumen est faible, même avec une ration riche en amidon et un pH bas dans le rumen, la déviation n'a pas lieu, la voie t11 suffisant à assurer l'hydrogénation des AGPI puisque dans ces conditions, la ∆9 isomérisation est elle aussi peu efficace à pH bas. En revanche, lorsqu'en plus de l'amidon, du c9,c12-C18:2 est ajouté dans la ration, la voie t11 devient insuffisante et c'est la voie t10 qui prend le relais. Le pyroséquençage 454 couplé à une régression multiple SPLS nous ont permis d'établir des corrélations entre les taxons identifiés et la proportion d'AG (t10 ou t11) dans le rumen. Il s'avère que les genres bactériens corrélés fortement et positivement aux AG t10 sont plus ou moins impliqués dans le métabolisme ruminal du lactate ainsi qu'au faible pH ruminal. Cependant, l'identification des taxons les plus corrélés aux AG t11 était moins précise, elle s'arrête à l'ordre des Clostridiales. Enfin, dans des conditions de déviation de la voie t11 à la voie t10, l'addition de vitamine E dans la ration des vaches n'a pas permis de restaurer un ratio déjà élevé. Ces résultats ont abouti à une meilleure compréhension de cette déviation et orientent vers une meilleure maîtrise en élevage. / Rumen biohydrogenation (BH) of polyunsaturated fatty acids (PUFA) is responsible of the production of trans intermediates found in ruminant products (mainly milk). There are two BH pathways leading to trans fatty acids (FA) with different biological properties: t11 isomers have beneficial effects for consumer's health and t10 isomers result in low milk fat content, representing a major constraint for farmers. In most conditions, t11 FA are the major trans FA, but in some conditions, especially with diets based on corn silage and including lipid supplements rich in PUFA, a shift from t11 to t10 pathway can occur with a significant increase of t10 isomers at the expense t11 isomers. The objective of this work was to explain modalities of this shift to better control it in animal production. Our results demonstrated that dietary factors responsible of the shift from t11 to t10 pathway are starch rapidly fermentable and c9, c12-C18:2 contents. When the amount of c9, c12-C18:2 present in the rumen is low, even though the diet is rich in starch and the pH is low in the rumen, the shift does not occur, t11 pathway being sufficient to ensure the hydrogenation of PUFA since in these conditions, the 9 isomerization is also poorly effective at low pH. However, when c9, c12-C18:2 is supplemented to the diet in addition to starch, t11 pathway becomes insufficient for FA BH, and t10 pathway becomes dominant. 454 pyrosequencing coupled to a multiple sPLS regression allowed us to establish correlations between some identified taxa and FA proportions (t10 or t11) in the rumen. It appears that bacterial genera that are strongly and positively correlated with t10 FA are more or less involved in the metabolism of ruminal lactate and also positively correlated with a low ruminal pH. However, identification of taxa correlated with t11 FA was less accurate, stopping at Clostridiales order. Finally, once the shift occurred, the subsequent addition of vitamin E was not able to counteract this process. These results lead to a better understanding of this shift to better control it in animal livestock.

Le veau nouveau-né possède un rumen peu développé et non fonctionnel. Au cours des premiers mois, les fonctions digestives s’établissent, avec l’implantation du microbiote composé majoritairement de bactéries, archées et protozoaires. Les objectifs de ce travail étaient doubles : i) caractériser et comprendre la séquence d’implantation taxonomique des microorganismes du rumen chez le veau par des techniques de biologie moléculaire et de dénombrement, ainsi que la séquence de mise en place des paramètres fermentaires (AGV et ammoniac) et des activités principales enzymatiques chez le veau en périodes pré- et post-sevrage, ii) étudier l’effet de l’addition de levures vivantes sur la mise en place de cet écosystème ruminal en périodes pré- et post-sevrage. D’une part, nos travaux ont permis de confirmer qu’à la naissance, le rumen chez le veau, est dépourvu de micro-organismes, d’AGV, d’activité xylanasique et amylasique, avec un pH proche de la neutralité et un Eh fortement positif. La colonisation du rumen se fait dès la naissance, pendant les 15 premiers jours de la vie de l’animal par un microbiote complexe prédominé par les bactéries (phyla Proteobacteria et Bacteroidetes) et comprenant aussi des archées (majoritairement Methanobrevibacter). En même temps, le Eh devient fortement négatif. Ces communautés entraînent la production de produits fermentaires grâce à leurs activités enzymatiques. Entre 15 jours et le sevrage, avec l’ingestion d’aliments solides, la composition du microbiote du rumen évolue pour se rapprocher de celle de ruminants adultes, sans atteindre pour autant la maturité en termes de densités et abondances relatives. A cette période, le phylum Bacteroidetes est majoritaire, avec le genre Prevotella. Après le sevrage de légers changements apparaissent sur certains paramètres fermentaires comme les AGV sans doute en raison d’une évolution du microbiote qui devient moins diversifié et plus adapté à la dégradation d’aliments solides. L’apparition, à partir de 90 jours, des protozoaires ciliés dans le rumen semble conditionnée par la présence d’animaux adultes à proximité. A 4 mois d’âge, l’écosystème ruminal tend à devenir proche de celui observé chez les animaux adultes en matière de paramètres fermentaires, activités enzymatiques et composition taxonomique du microbiote. D’autre part, nos travaux ont permis de conclure que, avant sevrage, une supplémentation en levures vivantes (Saccharomyces cerevisiae) diminue l’ingestion de concentrés, conduit à une apparition plus précoce de la communauté des protozoaires et une plus grande densité d’archées, mais a peu d'effets sur la densité et la diversité de la communauté bactérienne, à l'exception de variations d’abondances de quelques taxa mineurs. L’apport de levures entraîne une diminution de la protéolyse, une augmentation de la proportion d'acétate ruminal et une diminution de la proportion de propionate. Au cours de la période post-sevrage, les veaux supplémentés en levures consomment plus de foin et la densité en archées est plus importante alors qu’une réduction de la diversité et de la densité de la communauté bactérienne est observée, mais accompagnée d’une augmentation de l’abondance relative des bactéries dégradant l’amidon, les pectines, les protéines et majoritairement les parois cellulaires en fonction des substrats présents dans le rumen. Ces changements sont probablement à relier aux augmentations de l'activité xylanasique et de la proportion d'acétate. L’ensemble des résultats acquis dans ce travail de thèse a permis d’apporter un certain nombre de connaissances et une meilleure compréhension de la mise en place de l’écosystème ruminal chez le veau de race laitière en périodes pré- et post-sevrage, ainsi que quelques pistes pour orienter ou améliorer cette implantation pour une meilleure maîtrise de l’élevage des veaux d’élevage. / The newborn calf has a little and non-fonctional rumen. During the first months of life, digestive functions establish, in relationship with the colonization by a microbiota mainly composed of bacteria, archaea and protozoa. This study had two objectves: i) characterize and understand the sequence of establishment of ruminal microbiota in calves by molecular biology and counting techniques abd describe the appearance of fermentation parameters (VFA and ammonia) and enzyme activities during the pre- and post-weaning periods, ii) define the effect of yeast supplementation on the establishment of the ruminal ecosystem in pre-and post-weaning periods. On the one hand, our work confirmed that at birth, calf rumen is devoid of micro-organisms, AGV, xylanase and amylase activities, with a pH close to neutrality and a strongly positive Eh. From 2 to 15 days of age, the rumen is colonized by a complex microbiota dominated by bacteria (Proteobacteria and Bacteroidetes phyla) and also containing archaea (with mainly the Methanobrevibacter genus), and Eh becomes strongly negative. These communities result in the production of fermentation products due to their enzymatic activities. Between 15 days and weaning, with the ingestion of solid food, the composition of rumen microbiota changes to become closer to that of adult ruminants without reaching maturity in term of densities and relative abundances. At this time, the phylum Bacteroidetes is predominant with the Prevotella genus. After weaning, slight differences occurs on some fermentative parameters such as VFA, probably related to a change in the microbiota that becomes less diversified and more adapted to the degradation of solid food. From 90 days, the establishment of ciliated protozoa in the calf rumen seems conditioned by the proximity with adult animals. From 4 months of age, considering fermentation, enzymatic and taxonomic composition of the microbiota, the ruminal ecosystem tends to be similar to that observed in adult animals. On the other hand, our work showed that during the pre-weaning period, the supplementation with live yeast (Saccharomyces cerevisiae) results in a lower concentrate intake, an earlier establishment of ciliated protozoa and a higher archaeal community density, but poorly affects the density and diversity of the bacterial community, with the exception of changes in abundances of some minors taxa. Yeast supplementation reduces proteolysis, increases the proportion of acetate and decreases that of propionate. During the post-weaning period, yeast supplemented calves consumed more hay, had a higher archaeal density, but a lower diversity and density of the bacterial community with an increased relative abundance of fiber, protein, starch, pectine degrading bacteria compared to control according to the substrates present in the rumen. These changes are probably related to increases of the xylanolytic activity and the proportion of acetate. Taken together, results obtained in his thesis have improved knowledge and understanding of the establishment of the ruminal ecosystem in the dairy calf in pre- and post-weaning periods, and carried some possibilities to orientate or improve the ruminal establishment for better control of calves rearing.

Infestações com Rhipicephalus microplus, o carrapato dos bovinos, causam enormes prejuízos econômicos para a pecuária. Os carrapatos estão desenvolvendo resistência aos carrapaticidas que, além dessa desvantagem, deixam resíduos em carne e leite. Vacinas anticarrapato representam uma alternativa sustentável de controle de infestações, mas as atualmente disponíveis têm efeitos parciais e transitórios. Surge, assim, a necessidade de identificar novos antígenos vacinais. Para alcançar esse objetivo este trabalho explora o fato de que bovinos apresentam fenótipos contrastantes e herdáveis de infestações que são específicos de certas raças. Além disso, o nível de imunidade do hospedeiro afeta a transcrição de genes de glândulas salivares do carrapato, órgão que produz proteínas que medeiam o parasitismo. A hipótese de trabalho é a que os diferentes níveis da imunidade anticarrapato do hospedeiro afetam, também, a composição salivar do parasita. Assim, em carrapatos alimentando-se em hospedeiros resistentes as proteínas que são cruciais ao parasitismo poderão estar ausentes ou deficientes na sua saliva e por isso os carrapatos não terminam sua refeição de sangue. A neutralização dessas mesmas proteínas pela imunidade humoral pode ter o mesmo efeito e por isso, essas proteínas constituem bons antígenos vacinais. Assim, o objetivo do trabalho foi identificar novos antígenos vacinais em saliva de fêmeas e glândulas salivares de ninfas, machos e fêmeas de carrapatos alimentados em hospedeiros resistentes e suscetíveis, bem como em larvas não alimentadas oriundas de ovos de fêmeas alimentadas nestes mesmos hospedeiros. Para isso, foram empregadas abordagens de sequenciamento de nova geração \"RNA-Seq\" (454) e abordagens proteômicas, como análise diferencial em gel (DIGE) e Western Blots (imunoproteoma) seguido de sequenciamento de massa, além da tecnologia de identificação de proteínas multidimensionais (ou Multidimensional Protein Identification Technology, MudPIT) para descrever o proteoma das glândulas salivares e da saliva de fêmeas. A análise transcriptômica resultou no sequencimanto de 1.999.086 reads que permitiu identificar e classificar 11.676 sequências codificadoras (CDS), muitas das quais (3.600 CDS) contêm peptídeo sinal que é indicativo de secreção, portanto podendo estar presente na saliva e Resumo Gustavo Rocha Garcia apresentar função importante na hematofagia. Por meio de MudPIT, identificamos 321 proteínas salivares diferentes, além de 126 proteínas no DIGE e 266 proteínas nos imunoproteomas. Muitas dessas proteínas podem ser consideradas antígenos potenciais por estarem associadas com a hematofagia/parasitismo, tais como proteases, nucleases, inibidores de proteases, peptídeos antimicrobianos, proteínas de fixação, entre outros, inclusive proteínas ainda não caracterizadas. A maioria dos genes codificantes dessas proteínas está mais expressa em carrapatos alimentados em hospedeiros suscetíveis, principalmente em carrapatos machos. Além disso, muitas dessas proteínas não são reconhecidas por soros bovinos, inclusive soros de bovinos infestados, embora soros de bovinos infestados e resistentes ao carrapato apresente a maioria das reatividades. O conjunto dos resultados sugere que em nível de proteína a composição da saliva também é afetada pelos diferentes níveis de imunidade dos hospedeiros, além de variar com o ciclo de vida do carrapato. Desse modo, concluímos que as estratégias de investigação empregadas foram satisfatórias para identificar um conjunto de antígenos salivares do carrapato R. microplus que representam proteínas alvos para compor vacinas multicomponentes anticarrapato. / Infestation with Rhipicephalus microplus, the cattle tick, causes huge economic losses to livestock. Ticks are developing resistance to acaricides that, besides this disadvantage, leave residues in meat and milk. The anti tick vaccines represent a sustainable alternative of the infestations control, but the currently available has partial and transient effects. Thus arises the need to identify new vaccine antigens. To achieve this goal, this work explores the fact that cattle exhibit contrasting phenotypes and inheritable of infestations that are specific to certain breeds. Furthermore, the level of immunity of the host affects gene transcription tick salivary gland, organ that produces proteins that mediate the parasitism. The working hypothesis is that different levels of anti tick immunity of host affect also the salivary composition of the parasite. So in ticks feeding on resistant hosts the proteins that are crucial to parasitism may be absent or deficient in their saliva, and by this the ticks do not finish your meal blood. The neutralization of these same proteins by humoral immunity can have the same effect and by this, these proteins are good vaccine antigens. So, the aim of the study was to identify new vaccine antigens in saliva from females and salivary glands of nymphs, males and females of ticks fed on resistant and susceptible hosts as well as in unfed larvae originating from eggs of females fed on these same hosts. To this, were employed sequencing approaches of new generation \"RNA-Seq\" (454) and proteomic approaches, such as differential analysis in gel (DIGE) and Western Blots (immunoproteomics) followed by sequencing mass, besides the Multidimensional Protein Identification Technology (MudPIT) to describe the proteome of the salivary glands and saliva of females. The transcriptomics analysis identified 11,676 coding sequences (CDS), many of which (3,600 CDS) contain predicted signal peptide indicative of secretion, therefore may be present in saliva and provide an important function in blood feeding. Through MudPIT, we identify 321 different salivary proteins, besides 126 proteins in DIGE and 266 proteins in immunoproteomics. Many of these proteins may be considered as potential antigens to be associated with the blood meal/ parasitism, such as proteases, nucleases, protease inhibitors, antimicrobial peptides, proteins of attachment, among Abstract Gustavo Rocha Garcia others, including proteins not yet characterized. Most of the genes encoding of these proteins are more expressed in ticks fed on susceptible hosts, especially in male ticks. Moreover, many of these proteins are not recognized by bovine sera, including sera from infested hosts, although sera from infested and resistant host to tick present the most reactivities. The overall results suggest that in protein level, the composition of saliva is also affected by the different levels of immunity of the host, besides vary with the tick life cycle. Thus, we conclude that the research strategies employed were satisfactory to identify a set of tick salivary antigens from R. microplus that represent target proteins for composing anti tick multicomponent vaccines.